Geographic database including data for providing instructions about tollways

ABSTRACT

A navigation system provides a user thereof with warnings or advisories about toll gates that require exact change. The warnings or advisories are provided when the navigation system calculates a solution route to a destination specified by the user. The warnings or advisories are also provided when the user queries the navigation system about a particular specified portion of a road. The navigation system uses a geographic database that includes data about roads in a geographic region. The geographic database includes data about toll gates located along portions of roads including data about whether a toll gate along a portion or a road requires exact change.

REFERENCE TO RELATED APPLICATION

The present application is a divisional of Ser. No. 09/360,420, filedJul. 23, 1999, now U.S. Pat. No. 6,278,935 the entire disclosure ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to in-vehicle navigation systems and moreparticularly, the present invention relates to features provided byin-vehicle navigation systems relating to tollway information.

In-vehicle navigation systems are available that provide end users (suchas drivers of the vehicles in which the in-vehicle navigation systemsare installed) with various navigating functions and features. Forexample, some in-vehicle navigation systems are able to determine anoptimum route to travel by roads between locations in a geographicregion. Using input from the end user, and optionally from equipmentthat can determine one's physical location (such as a GPS system), anavigation system can examine various routes between two or morelocations to determine an optimum route to travel from a startinglocation to a destination location in a geographic region. Thenavigation system may then provide the end user with information aboutthe optimum route in the form of instructions that identify the drivingmaneuvers required to be taken by the end user to travel from thestarting location to the destination location. The instructions may takethe form of visual and/or audio instructions that are provided along theway as the end user is traveling the route. Some navigation systems areable to show detailed maps on computer displays outlining routes todestinations, the types of maneuvers to be taken at various locationsalong the routes, locations of certain types of features, and so on.

In order to provide these and other navigating functions, navigationsystems use geographic data. The geographic data may be in the form ofone or more databases that include data that represent physical featuresin a geographic region. The geographic database may include datarepresenting the roads and intersections in a geographic region and alsomay include information relating to the represented roads andintersections in the geographic region, such as turn restrictions atintersections, speed limits along the roads, street names of the variousroads, address ranges along the roads, and so on.

Although navigation systems provide many important features, therecontinues to be room for improvements. One area in which there is roomfor improvement relates to providing instructions about tollways.Although some prior navigation systems may provide instructions abouttollways, these prior systems have not provided instructions about exactchange requirements, whether a toll booth or gate along a tollway wasmanned, whether electronic fare collection was available, etc.Accordingly, when using such prior navigation systems, the end user maynot be prepared to make the appropriate payment at toll gatesencountered while driving.

Accordingly, there exists a need for navigation systems to provideinformation relating to toll collection requirements

SUMMARY OF THE INVENTION

To address these and other objectives, the present invention comprises anavigation system that provides a user thereof with warning messages oradvisories about toll gates that require exact change. The warningmessages or advisories are provided when the navigation systemcalculates a solution route to a destination specified by the user. Thewarning messages or advisories are also provided when the user queriesthe navigation system about a particular specified portion of a road.The navigation system uses a geographic database that includes dataabout roads in a geographic region. The geographic database includesdata about toll gates located along portions of roads, including dataabout whether a toll gate along a portion or a road requires exactchange.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a navigation system.

FIG. 2 is a block diagram showing more detail of some of the softwarecomponents of the navigation system shown in FIG. 1.

FIG. 3 illustrates a map showing a portion of the geographic regionrepresented by the geographic database of FIGS. 1 and 2.

FIG. 4 shows components of data records included in the geographicdatabase shown in FIGS. 1 and 2.

FIG. 5 is a drawing of a toll gate that illustrates one way that tollgate data can be represented in the geographic database of FIGS. 1 and2.

FIG. 6 is a drawing of a toll gate that illustrates another way thattoll gate data can be represented in the geographic database of FIGS. 1and 2.

FIG. 7 shows some of the components of a node data record that includestoll gate data represented in accordance with the method described inconnection with FIG. 6.

FIG. 8 is a block diagram showing some of the components of the outputof the route calculation function shown in FIG. 2.

FIG. 9 is an illustration of the navigation system of FIG. 1 showing animage on the display screen relating to an exact change warning message.

FIG. 10 is an illustration of the navigation system of FIG. 1 showing animage on the display screen including an exact change warning messageand a message about the availability of change at another toll gate.

FIG. 11 is an illustration of the navigation system of FIG. 1 showing animage on the display screen relating to an exact change warning messageand a message about a request to calculate an alternative route.

FIG. 12 is an illustration of the navigation system of FIG. 1 showing animage on the display screen relating to an exact change warning messageand a message about electronic toll collection.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS I.NAVIGATION SYSTEM-OVERVIEW

Referring to FIG. 1, there is a block diagram of a navigation system110. The navigation system 10 is installed in a vehicle 111, such as acar, bus, or truck, although in alternative embodiments, the navigationsystem 110 may be located outside of a vehicle or may be implemented invarious other platforms or environments, as described below. Thenavigation system 110 is a combination of hardware and softwarecomponents. In one embodiment, the navigation system 110 includes aprocessor 112, a drive 114 connected to the processor 112, and anon-volatile memory storage device 116 for storing programming 118 andpossibly other information. The processor 112 may be of any type used innavigation systems. Processors that are developed in the future may alsobe suitable.

The navigation system 110 may also include a positioning system 124. Thepositioning system 24 may utilize GPS-type technology, a deadreckoning-type system, or combinations of these or other systems, all ofwhich are known in the art. The positioning system 124 may includesuitable sensing devices 125 that measure the traveling distance, speed,direction, and so on, of the vehicle. The positioning system 124 mayalso include appropriate technology to obtain a GPS signal in a mannerwhich is known in the art. The positioning system 124 provides an outputto the processor 112. The output from the positioning system 124 is usedby the software 118 that is run on the processor 112 to determine thelocation, direction, speed, etc., of the navigation system 110.

The navigation system 110 also includes a user interface 131. The userinterface 131 includes appropriate equipment that allows the end user toinput information into the navigation system. This input information mayinclude a request to use the navigation features of the navigationsystem. For example, the input information may include a request for aroute to a desired destination. The input information may also includeother kinds of information. The equipment used to input information intothe navigation system may include an input panel 133, such as a keypad,a keyboard, buttons, switches, etc., or a microphone, etc., as well asappropriate software, such as voice recognition programming. The userinterface 131 also includes suitable equipment that provides informationback to the end user. This equipment may include a display 132,speakers, or other means.

Referring to FIGS. 1 and 2, the programming 118 may be loaded from thenon-volatile memory 116 into a RAM 134 associated with the processor 112in order to operate the navigation system. The programming 118 includesnavigation-related application software 119 that provides for thenavigating functions and features of the navigation system 110. Thenavigation-related application software 119 uses geographic data 140,possibly in conjunction with the output from the positioning system 124,to provide various navigation features and functions. Thenavigation-related application software 119 may include separatecomponent applications (also referred to as programs, subprograms,routines, or tools) that provide these various navigation-relatedfeatures and functions.

FIG. 2 shows some of the component applications for one embodiment ofthe navigation-related software 119 included in the navigation system 10of FIG. 1. These component applications may include geo-coding 141(wherein geographic coordinates from the positioning system 124 arerelated to data representing features represented in the geographic data140), route calculation 142, route guidance 144 (wherein detaileddirections are provided for reaching a desired destination), map display146, vehicle positioning 148 (wherein a vehicle position is related tothe geographic data 140), route preview 150 (wherein the end user isprovided with an outline or highlights of the calculated route), a tollquery function 151, and other functions 152. Other componentapplications, programs or tools may be included in the navigationprogramming 118.

The component applications of the programming 118 may work togetherthrough defined programming interfaces. The navigation-relatedapplication software 119 may access the geographic data 140 directly, oralternatively, the navigation application software 119 accesses thegeographic data 140 through an interface layer 154 and operating system156. The interface layer 154 and operating system 156 may be part of theprogramming 118 or may be provided separately.

In addition to the navigation-related applications 119, the programming118 may also include manager application software 155. The managerapplication software 155 provide interfaces to the hardware in the userinterface 131 and the positioning system 124. The manager applicationsoftware 155 may also coordinate requests for data from thenavigation-related applications 119.

In one embodiment, the separate applications of the programming 118 arewritten in the C programming language although in alternativeembodiments other programming languages may be used, such as C++, Java,Visual Basic, and so on.

II. THE GEOGRAPHIC MAP DATABASE

A. Overview.

Referring to FIG. 2, the geographic data 140 is organized into one ormore databases 162 and stored on a storage medium 164. The storagemedium 164 is installed in the drive 114 so that the geographic data 140can be read and used by the navigation system. The storage medium 164may be removable and replaceable so that a storage medium with anappropriate database 162 for the geographic region in which the vehicleis traveling can be used. In addition, the storage medium 164 may bereplaceable so that geographic data 140 on it can be updated easily.

In one embodiment, the geographic data are provided by NavigationTechnologies Corporation of Rosemont, Ill. However it is understood thatthe inventive concepts disclosed herein are not restricted to anyparticular source of data.

In one embodiment, the storage medium 164 is a CD-ROM disk. In analternative embodiment, the storage medium 164 may be a PCMCIA card inwhich case the drive 114 would be replaced with a PCMCIA slot. Variousother storage media may be used, including fixed or hard disks, DVDdisks or other currently available storage media, as well as storagemedia that may be developed in the future. The storage medium 164 andthe geographic data 140 do not have to be physically provided at thelocation of the navigation system. In alternative embodiments, thestorage medium 164, upon which some or all of the geographic data 140are stored, may be located remotely from the rest of the navigationsystem and portions of the geographic data provided via a communicationslink, as needed.

The map database 162 contains information about the roadway network inthe geographic region. In one embodiment, the map database 162 includesnode data and segment data. These data represent components of thephysical road network. Node data represent physical locations in thegeographic region (such as roadway intersections and other positions)and segment data represent portions of roadways between the physicallocations represented by nodes. (The terms “nodes” and “segments”represent only one terminology for describing these physical geographicfeatures and other terminology for describing these features is intendedto be encompassed within the scope of these concepts.) The informationincluded in the node and segment data entities is explained withreference to FIGS. 3-7.

FIG. 3 shows a map 216 of a portion of a geographic region 212represented by the geographic database 162 in FIG. 2. The map 216 inFIG. 3 illustrates part of the road network 220 in the geographic region212. The road network 220 includes, among other things, roads andintersections located in the geographic region 212. As shown in FIG. 3,each road in the geographic region 212 is composed of one or moresegments, 222(1), 222(2) . . . 222(n). In one embodiment, a road segmentrepresents a portion of the road. In FIG. 3, each road segment 222 isshown to have associated with it two nodes 223: one node represents thepoint at one end of the road segment and the other node represents thepoint at the other end of the road segment. The node at either end of aroad segment may correspond to a location at which the road meetsanother road, e.g., an intersection, or where the road dead ends.

In the geographic database 162, there is at least one database entry(also referred to as “entity” or “record”) for each road segmentrepresented in a geographic region. In the geographic database 162 thatrepresents the geographic region 212, there may also be a database entry(entity or record) for each represented node in the geographic region.FIG. 4 shows some of the components of these two kinds of data recordsthat are included in the geographic database 162 of FIG. 2.

Referring to FIG. 4, some of the components of a road segment datarecord 258 and two node data records 260(1) and 260(2) are shown. Eachroad segment data record and node data record may have associated withit information (such as “attributes”, “fields”, etc.) that describefeatures of the represented road segment or node. The road segmentrecord 258 includes a segment ED 258(1) by which the data record can beidentified in the geographic database 162. The road segment data record258 may also include data 258(2) that indicates the restrictions, ifany, on the direction of vehicular travel permitted on the representedroad segment. The road segment data record 258 includes data 258(3) thatindicates a speed limit or speed category (i.e., the maximum permittedvehicular speed of travel on the represented road segment). The roadsegment data record 258 may also include data 258(4) indicating whetherthe represented road segment is part of a controlled access road (suchas an expressway), a ramp to a controlled access road, a bridge, atunnel, a toll road, a ferry, and so on.

The road segment data record 258 also includes data 258(7) providing thegeographic coordinates (e.g., the latitude and longitude) of theendpoints of the road segment. In one embodiment, this data 258(7) is areference to the node data records 260(1) and 260(2) that represent thenodes corresponding to the endpoints of the represented road segment.

The road segment record 258 may also include or be associated with otherdata 258(5) that refer to various other attributes of the representedroad segment. The various attributes associated with a road segment maybe included in a single road segment record, or may be included in morethan one type of record which are cross-referenced to each other. Forexample, the road segment data record may include data identifying whatturn restrictions exist at each of the nodes which correspond tointersections at the ends of the road portion represented by the roadsegment, the name or names by which the represented road segment isknown, the street address ranges along the represented road segment, andso on. The various attributes associated with a road segment may beincluded in a single road segment record, or preferably are included inmore than one type of road segment record which are cross-referenced toeach other.

Each of the node data records 260 may have associated information (suchas “attribute”, “fields”, etc.) that allows identification of the roadsegment(s) that connect to it and/or its geographic position (e.g., itslatitude and longitude coordinates).

In a present embodiment, the geographic data 140 include data relatingto tollways. The data relating to tollways may include some or all ofthe following: an identification of the road segments that form part ofa tollway, the locations of toll gates, an indication whether a tollgate requires exact change, an indication whether a toll gate is manned,and an indication whether a toll gate accepts payment of a toll byelectronic means. (For purposes of this disclosure, the term “toll gate”is used to refer to any location along a road at which a toll iscollected for travel along the road. A “toll gate” does not require anactual physical gate or barrier. A toll gate may be part of a toll plazathat includes a plurality of individual toll gates.)

Toll gates (i.e., locations at which tolls are paid) may be representedin the geographic database 162 in various different ways. One way that atoll gate can be represented in the geographic database is explained inconnection with FIGS. 4 and 5. FIG. 5 is an illustration of a toll gatelocated along a road segment. According to this embodiment, a toll gateis represented as a feature of a represented road segment. The roadsegment illustrated in FIG. 5 is represented by a road segment datarecord 258 like the one shown in FIG. 4. Data about the toll gatelocated along the road segment is associated with the data recordrepresenting the road segment.

Referring to FIG. 4, the road segment data record 258 includes toll gatedata 258(6). As shown in FIG. 4, the toll gate data 258(6) includes data258(6)(1) indicating the location of the toll gate along the representedroad segment, data 258(6)(2) indicating the amount of the toll requiredat the toll gate, data 258(6)(3) indicating whether the toll gaterequires exact change, data 258(6)(4) indicating whether the toll gatehas an attendant on duty for taking tolls and making change, data258(6)(5) indicating whether the toll gate accepts payment of tolls byelectronic means, and possibly other data 258(6)(6). The data 258(6)(1)indicating the location of the toll gate along the represented roadsegment may be provided as absolute geographic coordinates of the tollgate, or alternatively, the location of the toll gate may be providedrelative to one or the other of the endpoints of the represented roadsegment along which the toll gate is located. For example, the locationof the toll gate may be defined as 30 meters from the left endpoint ofthe road segment. Alternatively, the location of the toll gate may bedefined in fractional portions of the length of the associated roadsegment, e.g., ⅜ of the length of the segment from the left end point.

Another way that the geographic database 162 can represent a toll gateis illustrated in connection with FIG. 6. In FIG. 6, the road segmentsleading into and away from the toll gate are represented in thegeographic database by separate road segment data records. Thus, thetoll gate illustrated in FIG. 6 corresponds to the position of the nodelinking the two road segments. Toll gate data can be associated with thenode data record that represents the node linking the two road segments.Some of the components of a node data record 260(3) located at theposition of a toll gate are illustrated in FIG. 7. The components of thenode data record 260(3) in FIG. 7 are similar to the components of thenode data records 260(1) and 260(2) shown in FIG. 4, except that thenode data record 260(3) includes toll gate data 260(3)(5). The toll gatedata 260(3)(5) associated with the node data record 260(3) includes someof the same. kinds of data as the toll gate data 258(5) associated witha road segment data record shown in FIG. 4. As shown in FIG. 7, the tollgate data 260(3)(5) associated with the node data record 260(3) includesdata 260(3)(5)(2) indicating the amount of the toll required at the tollgate, data 260(3)(5)(3) indicating whether the toll gate requires exactchange, data 260(3)(5)(4) indicating whether the toll gate has anattendant on duty for taking tolls and making change, data 260(3)(5)(5)indicating whether the toll gate accepts payment of tolls by electronicmeans, and possibly other data 260(3)(5)(6). The toll gate data260(3)(5) shown in FIG. 7 does not require that the location of the tollgate be separately specified because the location of the node 260(3)(1)can be taken as the location of the toll gate.

In the geographic database 162, toll gate data may be stored accordingto the way described in connection with FIGS. 4 and 5 (as a feature of aroad segment) or according to the way described in connection FIGS. 6and 7 (as a feature of a node). Alternatively, the geographic database162 can store toll gate data both ways in the same database. Otheralternative ways to represent toll gates can also be used. For example,toll gates can be stored as separate data entities.

B. The Route Calculation Application.

As stated above in connection with FIG. 2, the route calculationfunctions of the navigation system 110 are performed by the routecalculation application 142. According to one embodiment, a managerapplication 155 provides a request to the route calculation application142 to calculate a route. The request by the manager application 155specifies at least an origin and a destination. The request by themanager application 155 to the route calculation application 142 mayinclude additional information, such as desired intermediate stops,driver preferences, a start time, etc.

In one embodiment, the request to calculate a route may originate withthe end user. The end user may indicate a desired destination using theuser interface 131. Unless the end user also identifies an origin usingthe user interface 131, the current vehicle position may be taken as theorigin.

In one embodiment, the origin and destination are specified to the routecalculation function 142 relative to data in the geographic database.For example, the origin and destination may be specified at or along aroad segment represented by an identified road segment data record. Themanager application 155 may obtain from the vehicle positioningapplication 148 an identification of the road segment data record thatrepresents the road segment upon which the vehicle is currently located.The manager application 155 may obtain from the geo-coding application141 an identification of the road segment data record that representsthe road segment upon which the desired destination indicated by the enduser is located. (If the end user also specifies a desired origin, themanager application 155 may obtain an identification of the road segmentdata record that represents the road segment upon which the desiredorigin is located from the geo-coding application 141.) Thus, accordingto this embodiment, when the manager application 155 requests the routecalculation application 142 to calculate a route between a specifiedorigin and destination, it first obtains data from the geo-codingapplication 141 and possibly the vehicle positioning application 148that relates the origin and destination to data in the geographicdatabase 162. In an alternative embodiment, the functions of relatingthe end user specified destination and origin or the vehicle positionmay be performed by other routines including routines in the routecalculation application 142.

Given data that identify the positions of an origin and destination, theroute calculation application 142 calculates a route between the originand the destination. The route calculation application 142 may use anyof various means or algorithms for this purpose. Methods for calculatingroutes are disclosed in Ser. No. 09/047,698, filed Mar. 25, 1998, theentire disclosure of which is incorporated by reference herein. Forexample, the method used may include either the A algorithm or theDykstra algorithm. (The methods disclosed in the aforementioned patentapplication represent only some of the ways that routes can becalculated and the claimed subject matter herein is not limited to anyparticular method of route calculation. Any suitable route calculationmethod now known or developed in the future may be employed.)

Regardless of the method used, the objective of the route calculationapplication 142 is to develop a list identifying a continuous series ofroad segments that form a legally valid solution route between theorigin and destination. (A “legally valid solution route” conforms toknown traffic restrictions, such as one way streets, turn restrictions,etc.) The method used by the route calculation application 142 may bedesigned to optimize the solution route to meet one or morepredetermined criteria. Such criteria may include the least travel time,the shortest distance, the fewest turns, etc. If the method used by theroute calculation application 142 is designed to find a solution routethat is optimized for one or more criteria, then the solution route alsoideally meets these one or more criteria.

When using any of the aforementioned methods for calculating a solutionroute, the route calculation application 142 may explore severaldifferent alternative potential paths leading from the origin forinclusion in the solution route. The route calculation application 142may also explore several different alternative potential paths leadingback from the destination for inclusion in the solution route. Also, theroute calculation application 142 may explore several differentalternative potential paths leading from all or some of theintersections along potential portions of a solution route. For example,additional alternative paths may be identified and explored whenever anintersection having more than one valid successor road segment isencountered along an existing alternative potential solution path beingexplored. The number of different alternative potential solution pathscan increase rapidly. According to some route calculation methods, asroute calculation proceeds some alternative potential solution pathsbeing explored may be discarded based upon comparisons to other morepromising alternative potential solution paths. According to some routecalculation methods, as route calculation proceeds, further explorationof some alternative paths being explored may be suspended or deferred infavor of other, more promising, alternative potential solution paths.

As the route calculation application 142 evaluates different alternativepotential solution paths for inclusion in the solution route, it storesdata identifying the road segments included in each alternativepotential solution path. According to one present embodiment, databaseID's (e.g., segment ID 258(1) in FIG. 4) that identify the road segmentdata records that represent the road segments included in each differentalternative path are stored. The route calculation application 142 mayalso store additional data relating to each of the alternative potentialsolution paths, such as the total distance of all the road segmentsincluded in each alternative potential solution path, the total time oftravel for each alternative potential solution path, and so on.

After the route calculation application 142 has found a solution route,an output is provided to the route guidance application 144. FIG. 8 is adiagram representing the components of an output 400 of the routecalculation application 142. The route calculation output 400 containsan ordered list 410 identifying a plurality of road segment dataentities 258. The plurality of road segment data entities 258 in theoutput 400 of the route calculation application 142 are labeled, seg1,seg2, seg3 . . . seg(n). The plurality of data entities 258 representthe road segments that form the continuous navigable route between theorigin and the destination that has been calculated by the routecalculation application 142. Since these road segments form a continuousroute, each segment shares a node with its successor segment representedin the list 410. For example, as shown in FIG. 8, the segments “seg2”and “seg3” are shown to have a common node “N3.”

As mentioned above, the route calculation output 400 may include otherinformation 430 in addition to the ordered list of road segment dataentities.

In a present embodiment, the list 410 of data entities representing roadsegments included in the output 400 created by the route calculationapplication 142 is used as an input to the route guidance application144. The route guidance application 144 uses the data in the list 410 ofdata entities representing road segments, in conjunction with additionalinformation from the geographic database 162, to return navigationinformation to the manager application 155. The data returned by theroute guidance application 144 to the manager application 155 may besent directly to the user interface 131 for presentation to the enduser. Alternatively, the data returned by the route guidance application144 to the manager application 155 may be further processed byprogramming in the manager application 155. The presentation of routeguidance information to the end user via the user interface 131 may bein the form of audible instructions, visual textual instructions, visualgraphical instructions, or any combinations of these or other types ofinformation presentation.

According to a present embodiment, the data entities identified by thelist 410 in the route calculation output 400, which is created by theroute calculation application 142, can be examined for data relating totoll gates. More specifically, the toll gate data (e.g., 258(6)) in theroad segment data entities 258 in the list 410 or the toll gate data(e.g., 260(3)(5)) in the node data entities that represent the nodeslinking the roads in the list 410 can be examined to provide warningmessages and advisory features, as described below. The examination ofthe toll gate data can be performed by the toll query function 151.Alternatively, the examination of the toll gate data can be performed bya routine in the manager application 155 or by routine elsewhere in theprogramming 118.

III. TOLL WARNING EMBODIMENTS A. First Embodiment

According to a first embodiment, the end user uses the navigation system110 to calculate a route. As described above, there are various meansand algorithms by which the navigation system can calculate a route.After the navigation system has calculated a solution route for the enduser, a function (such as the toll query function 151) in the navigationsystem software 118 determines whether any portion of the solution routeincludes a toll gate at which exact change is required. This informationcan be determined using the data (258(6)(3) in FIG. 4 or 260(3)(5)(3) inFIG. 7) in the data included in the route calculation output 400. If thesolution route includes a toll gate at which exact change is required, awarning message is provided by the navigation system to the end user.The warning message may be provided via the user interface. The warningmessage may be audible or visual. In one embodiment, the warning messageis a visual warning accompanied by an audible warning. The warningmessage presents the end user with information that indicates that thesolution route includes a toll gate at which exact change is required.An example of a warning message produced in accordance with thisembodiment is shown in FIG. 9.

Referring to FIG. 9, there is shown a front panel 498 of the navigationsystem 110. In this embodiment, part or all of the navigation system 110may be mounted on or in the dashboard of the vehicle in which thenavigation system is installed. Accordingly, the front panel 498 of thenavigation system is accessible to the end user and observable by theend user.

Located on the front panel of the navigation system 110 are the displaypanel 132 and input panel 133 of the user interface 131. Portrayed onthe display panel 132 is an image 500. In this embodiment, the image 500includes a warning message 504. The warning message 504 includes textthat indicates the presence of a toll gate that requires exact changelocated along the solution route calculated by the route calculationfunction 142. In this embodiment, the display panel 132 also shows animage 510 of the calculated solution route. The image 510 shows thegeneral geometry of the calculated route to scale. In this embodiment,an indication 514 is depicted along the image 510 of the solution route.In this embodiment, the indication 514 is a circle that encompasses aportion of the image 510 of the solution route. The indication 514 isdepicted at the approximate location along the image of the solutionroute at which the toll gate at which exact change is required islocated. An arrow 516 may also be depicted pointing to the indication514.

In the embodiment shown in FIG. 9, the warning message 504 alsoindicates the approximate location along the solution route at which thetoll gate at which exact change is required is located. The locationalong the solution route at which the exact change toll gate is locatedcan be determined by the toll query function 151 by examination of thedata in the output 400 of the route calculation function 142.

As mentioned above, in some navigation systems, data may be availablethat indicate the amount of the toll required at some or all toll gatesin a geographic area. If such data are available to the navigationsystem 110, the warning message 504 provided by the navigation system tothe end user may also indicate the amount required at the toll gate atwhich exact change is required.

According to one embodiment, if the solution route calculated by thenavigation system includes more than one toll gate at which exact changeis required, the warning message provided by the navigation system tothe end user may indicate that there is more than one toll gate thatrequires exact change in the solution route. The navigation system maylist or otherwise indicate all the toll gates at which exact change isrequired along the solution route. If data are available to thenavigation system about toll amounts, the warning message provided bythe navigation system to the end user also may also indicate the amountrequired at each of the toll gates at which exact change is required.

According to another optional feature of this embodiment, if the tollgate at which exact change is required is located on a portion of thesolution route that follows a manned toll gate, the navigation systemmay provide an advisory warning to the driver advising the driver to besure to obtain the necessary change at the manned toll gate. FIG. 10shows the display panel 132 of the navigation system including anadvisory warning 518 of this type.

According to one embodiment, the warning message about exact change isprovided by the navigation system immediately after the route has beencalculated. According to this embodiment, the warning message aboutexact change may be provided by the navigation system before the enduser has traveled far along the solution route. In one embodiment, thewarning message about exact change is provided before detailed routeguidance is provided by the navigation system for following the solutionroute.

According to an optional feature of this embodiment, after thenavigation system 110 has provided the end user with a warning messagethat exact change is required along the solution route, programming inthe navigation system may request the end user to indicate whether analternative solution route should be calculated that does not includeany toll gates at which exact change is required. FIG. 11 shows thedisplay panel 132 of the navigation system including a request 520 ofthis type. If the end user indicates affirmatively (using an appropriatekey on the input panel 133, for example), the navigation system 110proceeds to calculate a new solution route. The navigation systemcalculates an alternative route that avoids any toll gate at which exactchange is required. When the new solution route is calculated to avoidany toll gate at which exact change is required, any segment thatincludes a toll gate at which exact change is required is avoided.Alternatively, the navigation system can calculate an alternative routethat includes a manned toll gate prior to any toll gate at which exactchange is required.

Another alternative feature provided by this embodiment relates toelectronic toll collection. This alternative feature is described inconnection with FIG. 12. Some jurisdictions or administrative areasprovide electronic toll collection systems. Various kinds of electronictoll collection systems are available. According to some systems, anelectronic transmitter in the vehicle communicates with a receiverlocated at the toll gate as the vehicle passes through the toll gate. Atoll is automatically paid as the vehicle passes. According to thisembodiment, the navigation system calculates a solution route, asdescribed above, and a function determines whether the solution routeincludes a toll gate at which exact change is required. If the toll gateat which exact change is required supports electronic toll payment, thenavigation system presents the end user with an image 528 on the displaypanel 132. In one embodiment, the image 528 includes a warning messageabout the presence of a toll gate at which exact change is requiredlocated along the solution route. The warning message in the image 528may also advise the end user that the toll gate supports payment byelectronic toll collection. Thus, if the end user has an electronic tollpayment device, he/she would be able to use the electronic toll paymentdevice at the toll gate at which exact change is required. If the tollgate at which exact change is required does not support electronic tollpayment, the image 528 may include an appropriate warning message soindicating.

{In an alternative embodiment, instead of a warning message, the image528 provided by the navigation system may be a symbol or icon, or acombination of a symbol or icon with a warning message.)

Some navigation systems provide a route preview function (150 in FIG.2). The route preview function provides the end user with an outline orhighlights of the calculated route. If the navigation system provides aroute preview function, the warning about exact change requirements maybe provided as part of the route preview.

According to an optional feature of this embodiment, the exact changewarning feature may be configurable. Some end users may not want to bewarned about exact change requirements. For example, some end users mayalways have ample amounts of change and therefore may desire not to beprovided with warnings about exact change requirements. If an end userdoes not want to be warned about exact change requirements, thenavigation system may be configured to omit providing such warnings. Thenavigation system may include a setup program or menu through which theend user may configure the navigation system to omit providing exactchange warnings. Some navigation systems may include a feature thatallows each driver of the vehicle in which the navigation system isinstalled to configure certain features so that the navigation system ispersonalized for each separate driver. If the navigation system can beconfigured for different drivers, then each driver may choose whether tohave exact change warnings.

According to another optional feature of this embodiment, after thenavigation system has provided the end user with an initial warningabout any exact change requirements along the solution route, thenavigation system may provide subsequent warnings to the end user. Thesesubsequent warnings may be provided at intervals while the end user isdriving along the calculated route. These subsequent warnings may beprovided as part of the route guidance function 144. The intervals maybe based upon time (e.g., every 5 minutes) or distance (e.g., every 5miles). A subsequent warning may also be provided as the vehicleapproaches a manned toll gate along the solution route at which changemay be obtained for the later toll gate at which exact change isrequired. A final warning may also be provided as the vehicle approachesthe toll gate at which exact change is required. When the final warningis provided, the navigation system may accompany the final warning witha request to the end user to indicate whether an alternative routeshould be calculated that avoids the toll gate at which exact change isrequired. If the end user indicates affirmatively to the requestaccompanying the final warning, the navigation system calculates analternative route that avoids the toll gate at which exact change isrequired. The alternative route calculated by the navigation systemavoids any toll gate at which exact change is required or alternatively,the navigation system calculates an alternative route that includes amanned toll gate prior to any toll gate at which exact change isrequired.

B. Second Embodiment

According to a second embodiment, the end user uses the navigationsystem to calculate a route, as described above. After the navigationsystem has calculated a solution route for the end user, a function inthe navigation system software 118 determines whether any portion of thesolution route includes a toll gate at which exact change is required.According to this embodiment, the function transmits a wireless messagefrom the vehicle to a service provider. Any suitable form of datatransmission may be used, such as cellular, PCS, satellite, radio, etc.The message transmitted from the vehicle to the service providerincludes data that indicate the solution route calculated by thein-vehicle navigation system. The data may include the entire list ofdata entities that represent road segments in the solution route, oralternatively, the data may include an outline or other form ofcompressed representation by which the service provider can be informedof the solution route. After receiving the solution route, the serviceprovider determines whether any portion of the solution route includes atoll gate at which exact change is required. The service providerqueries a database associated with the service provider that includesup-to-date information about tolls, etc. After the service providerdetermines whether the solution route includes any toll gates at whichexact change are required, a message is transmitted from the serviceprovider to the navigation system in the vehicle. The message indicateswhether the solution route includes one or more toll gates at whichexact change is required. The navigation system then provides a warningmessage to the end user. The warning message provided by this embodimentmay be similar or identical to the warning messages described above inconnection with the previous embodiment. All the other features andfunctions described above in connection with the previous embodiment mayalso be provided with this embodiment. Messages may be transmittedbetween the vehicle and the service provider as needed.

An advantage of this embodiment is that the information about tolls canbe maintained in a central location. This may facilitate the updating ofthe information about tolls more frequently.

This alternative embodiment, in which a message is transmitted to acentral database, may be used when the in-vehicle navigation system doesnot have data about toll gates available locally (i.e., in the vehicle).This alternative embodiment in which a message is transmitted to acentral database may also used when the in-vehicle navigation system hasdata about toll gates available locally, but it is desired to check withthe service provider for more up-to-date information.

C. Third Embodiment

According to a third embodiment, the end user may query the navigationsystem installed in the vehicle which the end user is driving aboutwhether a particular road segment includes a toll gate at which exactchange is required. This may occur under various circumstances. Forexample, while driving along a tollway, a driver may wish to exit fromthe tollway at a particular exit ramp ahead but is unaware whether theexit ramp has a toll gate at which exact change is required. In thisexample, the driver may not be following a route calculated by thenavigation system (in which case the navigation system would havealready provided a warning about the upcoming toll gate). For example,the driver may not have requested the navigation system to calculate aroute. Alternatively, the driver may be considering a departure from aroute calculated by the navigation system. Alternatively, the navigationsystem may have been configured to omit warnings about toll gates atwhich exact change is required, as described above.

Regardless of the reason, the end user can query the navigation systemabout whether a particular road segment includes a toll gate at whichexact change is required. The navigation system provides a means bywhich the query from the driver can be received. This may includeappropriate menus and programming in the user interface. The menus andprogramming allow the end user to identify a particular portion of aroad and to inquire whether a toll gate at which exact change isrequired is located along the identified portion of the road. When thequery is received, the navigation system accesses the data in thegeographic database relating to the identified road portion. The datarelating to the identified road portion is examined for an indicationwhether a toll gate at which exact change is required is located alongthe identified road portion. If the identified road portion includes atoll gate at which exact change is required, the navigation systemprovides a warning to the end user. The warning provided by thenavigation system may be accompanied by an indication of the amount ofexact change required at the toll gate (if such information isavailable). The warning provided by the navigation system may beaccompanied by a request to indicate whether an alternative route shouldbe calculated that avoids the toll gate at which exact change isrequired. In this embodiment, if the identified road portion does notinclude a toll gate at which exact change is required, the navigationsystem provides an indication to the end user that the identified roadportion does not include a toll gate at which exact change is required.

According to an alternative method of operation for this embodiment,when the end user queries the navigation system about whether a portionof a road includes a toll gate at which exact change is required, thenavigation system transmits a wireless message to a service provider inorder to obtain up-to-date information about the presence of any tollgate on the identified route. This message may be transmitted asdescribed above in connection with the second embodiment. The message tothe service provider identifies the road portion. The service providerchecks a central database, formulates an answer and transmits theinformation to the in-vehicle navigation system. Upon receiving theinformation from the service provider, the in-vehicle navigation systemprovides the information to the end user. This alternative embodiment inwhich a message is transmitted to a central database may be used whenthe in-vehicle navigation system does not have data about toll gatesavailable locally (i.e., in the vehicle). This alternative embodiment inwhich a message is transmitted to a central database may also be usedwhen the in-vehicle navigation system has data about toll gatesavailable locally, but it is desired to check with the service providerfor more up-to-date information.

D. Fourth Embodiment

According to a fourth embodiment, when requesting the navigation systemto calculate a solution route to a desired destination, the end user mayspecify that toll gates at which exact change is required be avoided.The end user may specify this preference when indicating a desireddestination. When the navigation system proceeds to calculate a solutionroute, it avoids including any road segment that includes a toll gaterequiring exact change. According to an optional feature of thisembodiment, the navigation system may be configurable by the end user toautomatically avoid toll gates at which exact change is required. If thenavigation system is configured in this manner, solution routes will becalculated avoiding toll gates at which exact change is required bydefault.

According to an optional feature of this embodiment, the end user may beable to specify that toll gates that :require exact change and that donot accept electronic toll payment be avoided. The end user may specifyboth these preferences when indicating a desired destination. When thenavigation system proceeds to calculate a solution route, it avoidsincluding any road segment that includes a toll gate requiring exactchange and that does not accept electronic payment.

E. Additional Alternative Embodiments

In addition to in-vehicle navigation systems, the features describedabove can be provided on other types of computing platforms that providenavigation-related features. For example, navigation applicationprograms may be provided on personal computers, including desktopcomputers and portable computers. Computer-based navigation applicationprograms may also be provided on networks, including wireless networksand the Internet. Computer-based navigation application programs mayalso be included on hand-held computer devices, such as personal digitalassistants, telephones, pagers, and so on. In addition, computer-basednavigation application programs may be included on special purposeelectronic devices, such as personal navigation systems.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting and that it is understood that thefollowing claims including all equivalents are intended to define thescope of the invention.

We claim:
 1. A geographic database stored on a computer-readable mediumcomprising: data about roads in a represented geographic region,including data indicating the locations of said roads, data indicatingdirections of travel along said roads, data indicating turn restrictionsat intersections of said roads, and data indicating names of said roads;data about toll gates located along said roads; and data indicatingwhether each of said toll gates requires exact change.
 2. The inventionof claim 1 wherein said data about toll gates located along said roadsare associated with data records that represent said roads.
 3. Theinvention of claim 1 wherein said data about toll gates located alongsaid roads are associated with data records that represent intersectionsalong said roads.
 4. The invention of claim 1 wherein said geographicdatabase further comprises: data indicating whether a toll gate has anattendant on duty.
 5. The invention of claim 1 wherein said geographicdatabase further comprises: data indicating whether a toll gate acceptspayment of tolls by electronic means.
 6. The invention of claim 1wherein said geographic database is installed in a vehicle.
 7. Theinvention of claim 1 wherein said geographic database is installed on aserver.
 8. A geographic database stored on a computer-readable mediumand used in an in-vehicle navigation system, the geographic databasecomprising: data about roads in a represented geographic region; dataabout toll gates located along said roads; and data indicating whethereach of said toll gates requires exact change.
 9. The invention of claim8 wherein said data about toll gates located along said roads areassociated with data records that represent said roads.
 10. Theinvention of claim 8 wherein said data about toll gates located alongsaid roads are associated with data records that represent intersectionsalong said roads.
 11. The invention of claim 8 wherein said geographicdatabase further comprises: data indicating whether each of said tollgates has an attendant on duty.
 12. The invention of claim 8 whereinsaid geographic database further comprises: data indicating whether eachof said toll gates accepts payment of tolls by electronic means.
 13. Theinvention of claim 8 wherein said geographic database is installed in avehicle.
 14. The invention of claim 8 wherein said geographic databaseis installed on a server.
 15. A geographic database stored on acomputer-readable medium and used in an in-vehicle navigation system,the geographic database comprising: data about roads in a representedgeographic region; data about toll gates located along said roads; anddata by which a determination can be made whether each of said tollgates requires payment of tolls by exact change and that payment byelectronic means is not supported.
 16. The invention of claim 15 whereinsaid data about toll gates located along said roads are associated withdata records that represent said roads.
 17. The invention of claim 15wherein said data about toll gates located along said roads areassociated with data record that represent intersections along saidroads.
 18. The invention of claim 15 wherein said geographic databasefurther comprises: data indicating whether each of said toll gates hasan attendant on duty.
 19. The invention of claim 15 wherein saidgeographic database is installed in a vehicle.
 20. The invention ofclaim 15 wherein said geographic database is installed on a server.